Leave it to the Hindu American Foundation. It has launched a "Take Back Yoga" campaign "to acquaint Westerners with the faith that it says underlies every single yoga style followed in gyms, ashrams and spas: Hinduism."
According to an article in The New York Times, the group says it isn't trying to convert Americans to Hinduism but merely wants to acquaint yoga practitioners to its roots in their faith's ancient traditions. The following video shows how yoga is seen by some American fundamentalists. Sort of like Reefer Madness: